The present invention relates to a pneumatic vehicle tire, especially for commercial vehicles, having a radial carcass, the load-carriers of which are made of steel or of a material of comparable high strength, and the ends of which are anchored in the tire beads by being looped around pull-resistant bead cores. The tire has a centrally disposed tread strip that has a recessed portion on each side. The tire also has a multi-ply belt, which to the sides extends into the recessed portions, and which has load-carriers made of steel or of a material of comparable high strength. A low-damping rubber layer can be disposed between plies of the belt.
A tire of this general type without a low-damping rubber layer between plies of the belt is disclosed, for example, in German Offenlegungsschrift 33 13 535Rohde corresponding to co-pending U.S. Pat. application Ser. No. 233,834-Rohde filed Aug. 16, 1988, belonging to the assignee of the present invention, and with such a low-damping rubber layer in German Offenlegungsschrift 34 30 501 Rohde et al corresponding to U.S. Pat. No. 4,671,333-Rohde et al dated June 9, 1987, belonging to the assignee of the present invention. Such tires have given best results when used with commercial vehicles. By providing a step in the shoulder region, and by having the belt plies extend laterally into the stepped portions, as well as by possibly introducing a low-damping rubber layer between plies of the belt, a tire having a reduced resistance to rolling was provided with which considerable savings in fuel could be obtained. The reduced resistance to rolling was primarily achieved by reducing the build up of heat due to unavoidable deformations of the tread strip zone during driving operation. The rubber cushions, which in the shoulder region shift in a wedge-like manner between the ends of the belt and the carcass, effect in this region a balancing-out between the stiff belt ply unit and the more flexible carcass.
German Auslegeschrift 10 07 644 Fletcher dated May 2, 1957 discloses a vehicle tire, especially for aircraft, where radially outwardly from an eight-ply diagonal carcass of textile fabric there is disposed a belt of steel cord fabric, with a resilient rubber underlayer of a carcass rubber mixture being disposed between them. The belt plies extend at an angle of 45.degree. relative to the circumferential direction of the tire. The rubber underlayer serves to prevent a detachment of the belt from the carcass due to the overall rigidity of the tire and the relative movement between the tread strip and the carcass resulting therefrom. This known rubber underlayer is at least 2 to 5 mm thick.
It is an object of the present invention with a pneumatic vehicle tire of the aforementioned general type, to further reduce the build up of heat in the area of the tread strip without the remaining driving properties suffering thereby.